1. Technical Field
The present invention generally finds application in the field of sport and leisure accessories, and particularly relates to a bicycle saddle structure to be attached to a bicycle frame or the like and a method of assembly thereof.
2. Description of Related Art
Bicycle saddles of the above mentioned type typically include a shell of a substantially rigid material, having a narrow front portion and a widened rear portion, a user supporting top surface and rails, generally made of thread-like metal material for connection of the shell to a bicycle frame.
The shell is generally attached to the rails at its front and rear end portions via suitable anchor means.
In one known method of attachment, the rails are fixed to the shell first at the rear portion and then at the front portion thereof.
This step is carried out by forcing the specially shaped front portion of the rails into a suitable seat formed in the front part or “nose” of the shell.
For this purpose, the shell is introduced in a special tool that is operable to cause temporary elongation thereof and then sliding of the front portion of the rails along a ramp located at the nose that acts as a lead-in surface for the front portion of the rails into its seat.
The forced sliding motion of the rails along the ramp is caused by a predetermined load operating thereon to cause the required compressive deformation needed to move the front portion of the rails beyond the lower limit of such ramp and finally into its seat.
Now, once the lower limit of the ramp has been reached, the rails are released and move back into the unstressed configuration, and the special tool is also released to restore the shell to its initial configuration, thereby stabilizing the shell/rails connection.
This assembly method suffers from the apparent recognized drawback that both the shell and the rails are subjected to considerable stresses that often cause their failure, as well as plastic deformation that affects their mechanical properties.
Furthermore, as the rails fit into their seat, they almost instantaneously change from a maximum compression condition to a minimum compression condition, thereby transforming the elastic energy accumulated during deformation into kinetic energy which is impulsively transferred to the shell.
Therefore, the shell will be struck a heavy blow, which may often cause cracking or even, in extreme cases, failure.
In an attempt to obviate the above drawbacks, saddles have been developed in which the shell/rails connection involves no tensile and/or compressive stress.
Saddles are commonly available on the market, in which the rails are secured to the shell, at their respective front portions, by placing the rails onto the shell and later securing their front portion to the nose via a flexible support that can be removably attached to the shell by screw connection means.
Thus, the seat for the front portion of the rails will be defined by the support and the bottom surface of the shell. A similar arrangement is disclosed, for instance, in EP 1521702.
While this arrangement ensures quick and simple connection between the rails and the shell, it still suffers from the drawback that the holding force of the connection is only provided by the nose piece and particularly by the fastener member, which is apparently a weak point of the whole structure.
Therefore, the stresses that are typically transmitted to the saddle during riding may lead with time to failure at the fastening point and to disconnection of the shell from the rails, thereby apparently affecting rider's safety.